Character Encoding and UTF-8: What Every Developer Should Know

Character encoding is fundamental to how computers store and display text. Misunderstanding encoding leads to garbled text, broken characters, and data corruption. UTF-8 has become the dominant encoding standard for the modern web.

What Is Character Encoding?

Computers store everything as numbers. Character encoding is the system that maps numbers to characters. Different encoding systems assign different numbers to the same characters.

The History

ASCII (1963)

The original standard, using 7 bits to represent 128 characters. It covers basic English letters, digits, and common symbols, but nothing else.

Extended ASCII and Code Pages

Various 8-bit encodings added 128 more characters for specific languages. This created incompatibility problems when sharing files between different systems.

Unicode (1991)

Unicode assigns a unique number (code point) to every character in every language, plus symbols, emoji, and more. It currently defines over 150,000 characters.

UTF-8 (1993)

UTF-8 is a variable-length encoding for Unicode. ASCII characters use 1 byte, while other characters use 2-4 bytes. It is backward-compatible with ASCII and is the most widely used encoding on the web.

Why UTF-8 Matters

Over 98% of all web pages use UTF-8 encoding. It supports every language, is efficient for English text, and is the default encoding for HTML5, JSON, and most modern protocols.

Best Practices

1. Always declare UTF-8 encoding in your HTML:
2. Save your source files as UTF-8
3. Configure your database to use UTF-8 (utf8mb4 in MySQL)
4. Set Content-Type headers: Content-Type: text/html; charset=utf-8
5. Use UTF-8 when reading and writing files in your code